CALGARY, ALBERTA–(Marketwire – Feb. 20, 2013) – Celtic Exploration Ltd. (“Celtic“) (CLT.TO) is pleased to announce that under the terms of the Investment Canada Act, the Minister of Industry has approved the proposed acquisition of Celtic by a subsidiary of ExxonMobil Canada Ltd. (“ExxonMobil Canada“). No further regulatory approvals are required.

The proposed acquisition of Celtic by ExxonMobil Canada is to be carried out by way of a plan of arrangement under the Business Corporations Act (Alberta) (the “Arrangement“) and the Arrangement is expected to be completed on or about February 26, 2013, assuming the satisfaction or waiver of the conditions specified in the arrangement agreement dated October 16, 2012 (the “Arrangement Agreement“) between Celtic, ExxonMobil Canada, ExxonMobil Celtic ULC and Kelt Exploration Ltd.

The register maintained by the trustee of the 5.00% convertible unsecured subordinated debentures of Celtic due April 30, 2017 (the “Debentures“) will be closed on February 20, 2013. Holders of Debentures will not be able to convert Debentures into common shares of Celtic after such time and will instead be entitled to receive the consideration provided for under the Arrangement.

About Celtic

Celtic is a Calgary, Alberta, Canada-based oil and gas company focused on exploration, development and production of crude oil and natural gas resources primarily in west central Alberta. Celtic holds large acreage positions in the Montney and Duvernay resource gas plays. Throughout its history, Celtic has a proven track record of growing reserves, production and the underlying value of the company for its shareholders. The common shares of Celtic are listed on the Toronto Stock Exchange under the symbol CLT.

Cautionary Statement on Forward-Looking Statements and Information

This press release contains forward-looking statements and forward-looking information within the meaning of applicable securities laws. The use of any of the words “expect”, “anticipate”, “continue”, “estimate”, “objective”, “ongoing”, “may”, “will”, “project”, “should”, “believe”, “plans”, “intends” and similar expressions are intended to identify forward-looking statements or information. In particular, this press release contains forward-looking statements and information concerning the ability of the parties to satisfy the conditions to, and to complete, the Arrangement and the anticipated timing of completion of the Arrangement.

In respect of such forward-looking statements and information, Celtic has provided such statements and information in reliance on certain assumptions, including assumptions as to the ability of the parties to satisfy, in a timely manner, the conditions specified in the Arrangement Agreement. Although Celtic believes that the assumptions on which such forward-looking statements and information are based are reasonable, undue reliance should not be placed on the forward-looking statements and information because there can be no assurance that they will prove to be correct.

Since forward-looking statements and information address future events and uncertainties, by their very nature they involve inherent risks and uncertainties. Actual results could differ materially from those currently anticipated due to a number of factors and risks. These factors and risks include, but are not limited to, the risk that the conditions to the completion of the Arrangement set forth in the Arrangement Agreement may not be satisfied or waived in a timely manner or at all; and the risk that the Arrangement may not close when planned or at all on the terms and conditions set forth in the Arrangement Agreement.

Readers are cautioned that the foregoing list of factors is not exhaustive. Additional factors that could affect Celtic are included in the documents filed by Celtic with the applicable securities regulatory authorities and may be accessed through the SEDAR website at www.sedar.com.

Celtic’s actual results, performance or achievement could differ materially from those expressed in, or implied by, these forward-looking statements and information and, accordingly, no assurance can be given that any of the events anticipated by the forward-looking statements and information contained in this press release will transpire or occur, or if any of them do so, what benefits may be derived therefrom. The forward-looking statements and information contained in this press release are made as of the date hereof and Celtic undertakes no obligation to update publicly or revise any forward-looking statements or information, whether as a result of new information, future events, or results or otherwise, other than as required by applicable securities laws.